World Journal of Pharmaceutical research - WJPR!

Manish Gunjan World Journal of Pharmaceutical research
of human and onc of the oldest documented diseases. An estimated 35 to45 percent of all
U.S. women and 20 to 30 percent of all U.S. men are trying to lose weight at any given time,
spending up to $40 billion each year to do so. Some of these people do not even need to lose
weight. Others need to lose weight but not successful. Still others are successful. Weight- loss
advice, then, does not apply equally to all overweight people. Some people may risk more in
the process of losing weight than in remaining overweight. Others may reap significant health
benefits with just modest weight loss. (4) The overweight problem is due to an actual increase
in the fat component, or it can be due to malfunctioning glands. Today, it is estimated that
there are more than 250 million obese people worldwide, equivalent to seven percent of the
adult population. (5) In the United States, data from the second National Health and Nutrition
Examination Survey (NHANES II) were used to define obesity in adults as a BMI of 27.3
kg/m2 or more for women and 27.8 kg/m2 or more for men. These definitions were based on
the gender-specific 85th-percentile values of BMI for persons 20 to 29 years of age. The
WHO classification assigns an increasing risk for comorbid conditions—including
hypertension, type 2 (non-insulin-dependent) diabetes mellitus, and cardiovascular disease--
to persons with higher BMIs (see Table 1) relative to persons of normal weight (i.e., those
with a BMI between 18.5 kg/m2 and 25 kg/m2).The WHO criteria for overweight is (BMI
25 kg/m 2 ) and obesity ( 30 kg/m2), 67% of men and 62% of women are overweight . (6)
Food intake is modified by a multitude of factors – physiological, psychological, and social,
etc. Meal size seems to be controlled by a feedback loop in which signals from the
gastrointestinal tract are transmitted to the hypothalamus after relay in the brainstem. An
important afferent signal is cholecystokinin – a peptide secreted by the duodenum in response
to mechanical and chemical stimuli. Cholecysokinin acts locally on cholecystokinin receptors
in the gastrointestinal tract, the signal being transmitted to the brainstem by the vagus. The
effect is to decrease food intake. Circulating cholecystokinin does not cross the blood-brain
barrier but the peptide is also a neurotransmitter and acts on cholecystokinin B receptors in
the brain to function as a satiety factor. Insulin stimulates leptin release from fat cells and it
enters the CNS where it can decrease food intake by affecting the actions of NPY. However,
insulin may also, in some circumstances, increase food intake, presumably indirectly, by an
effect on blood glucose. Thus patients with type 2 diabetes mellitus usually gain weight when
treated with insulin or sulfonylureas – an effect that is clinically important. (7) Current
management of obesity by pharmacotherapy includes noncentrally acting antiobesity agents
such as Orlistat (Xenical), which inhibits the action of the intestinal lipase enzymes and
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